962
FXUS61 KOKX 012346
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
746 PM EDT Wed May 1 2024

.SYNOPSIS...
A frontal boundary remains in the vicinity tonight, pushing east
on Thursday, followed by high pressure Friday into Friday night.
The high moves off the coast Saturday as a cold front
approaches. This front moves through Sunday night into Monday
morning, then stalls south of the region. The front moves back
north as a warm front Tuesday into Wednesday.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
-- Changed Discussion --
Area of stratus has moved into the area off the ocean and was
drifting and expanding to the west. Increased cloud cover across
Long Island and then into Connecticut and northeastern New
Jersey.

A nearly stationary frontal boundary remains in the vicinity
tonight, though dry conditions should prevail. There may be some
weak lift towards morning to account for some drizzle, but
right now, think that this will more likely take the form of fog
and low clouds. Went with patchy fog, but it could be more
widespread for eastern areas as we head toward daybreak.

With clouds in the area tonight and a light southeasterly flow,
low temperatures will be just a degree or two above normal for
this time of year, in the upper 40s to lower 50s
-- End Changed Discussion --

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/...
-- Changed Discussion --
Low pressure passes well north of the area Thursday, helping to
push the frontal boundary through the forecast area during the
day. The low, and associated developing shortwave dive
southeast, passing east of the area overnight tonight.
Thereafter, high pressure builds in from southeastern Canada at
the surface while a high amplitude ridge over the eastern Great
Lakes moves slowly east, but its ridge axis remains just west or
begins to enter the forecast area by the daybreak Saturday.
Have gone with a dry forecast based on weak dynamics and track
of the low and upper shortwave.

The main forecast challenge will be the high temperatures for
Thursday. The area may be warm sectored for a brief time during
the day Thursday, and the southwesterly to westerly flow that
develops may help to bring in warm temperatures for this time of
year. Given previous discussion on how cool NBM has been
lately, and looking at NBM probabilities of greater than 75 and
then 80 degrees, thinking is that much of New York City and
points north and west will see highs in the low 80s, while
southern portions of the city much of Long Island, and
southeastern Connecticut remain in the upper 60s to lower 70s.
However, there is a great amount of spread in the NBM, with 15
to as much as 18 degree difference noted between the 25th and
75th percentiles. Therefore, there is a rather large amount of
uncertainty with the temperature forecast.

Seasonably warm conditions expected Thursday night with lows
generally in the 50s region-wide. Temperatures drop back to near
normal on Friday.
-- End Changed Discussion --

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
-- Changed Discussion --
An upper level ridge over the area Friday night into Saturday,
as the flow becomes near zonal into early next week. A longwave
upper trough across eastern Canada amplifies into the northeast
Tuesday and moves off shore Wednesday as another upper ridge
builds to the west of the area and moves into the region
Wednesday. At the surface high pressure along the northeast and
mid Atlantic shifts slowly east into Saturday as a cold front
approaches. This front tracks across Sunday night into Monday,
and becomes nearly stationary as the flow becomes parallel to
the boundary. A period of some heavier showers will be possible
Sunday as precipitable water values increase to 1.3 inches. Then
Tuesday into Wednesday high pressure builds south from the
Hudson Bay region of Canada into the eastern Great Lakes. With a
deep low tracking northward from the northern plains into
southern Canada Tuesday into Wednesday the stalled cold front
will move slowly northward as a warm front. There is uncertainty
as to the movement of the front as high pressure, and an upper
ridge will be in place. Temperatures Friday night through Sunday
will be around 5 degrees above normal, and then Sunday night
into Wednesday 5 to 10 degrees above normal. For highs and lows
Monday through Wednesday used a blend of NBM and NBM 75th
percentile to raise temperatures a few degrees above the NBM.
Depending on the movement of the warm front next week, there is
a chance that a few locations will have a record high low Monday
night into Tuesday morning.
-- End Changed Discussion --

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
Weak high pressure will remain east of the area, meanwhile,
a weak frontal system approaches from the west. There is some
uncertainty as to how quickly the associated warm front/cold
front get through the area on Thursday, which could lead to wind
timing and intensity issues. The front may struggle to get east
of the coastal terminals.

Mainly VFR to start, however we are starting to see some IFR
cigs move in across portions of Long Island. Widespread
IFR/LIFR conditions are forecast to develop this evening into
the early morning hours Thursday. Improvement to VFR is forecast
through the morning Thursday. It may take into early afternoon
across the far eastern terminals.

SE winds generally 10kt or less through the overnight, then
gradually veering from east to west on Thursday as a frontal
system attempts to work across the area. The westerly wind shift
may remain west of the KLGA and KJFK for much of the day,
before going around in the early evening. There is fair amount
of uncertainty as to how far east the west winds get on
Thursday. W/NW winds 10-15kt G20kt are possible for those
locations that do come around. By late day/early evening, all
the terminals should become more westerly or northwesterly.

 ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

There is only low to medium confidence on the timing of IFR
ceilings tonight.

The timing of the wind shift to the W/NW on Thursday could be
delayed significantly, especially at KLGA and KJFK. Warm front
could get hung up across the area during the daytime hours.

OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY...

Friday: VFR.

Saturday: Mainly VFR. Chance of showers and MVFR cond in the
afternoon, becoming likely overnight.

Sunday...Chance of MVFR or lower in showers. ESE winds G15-20kt.

Monday...VFR.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
No changes to winds and seas at this time. Stratus has moved
over the ocean waters from the east. Patchy fog may develop over
the ocean waters later tonight, however, visibilities are
expected to remain above 1 nautical mile.

A weak pressure gradient remains in place, with an extended
period of conditions below SCA levels tonight through Monday
night.
-- End Changed Discussion --

&&

.HYDROLOGY...
There are currently no hydrologic concerns through early next
week.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$

SYNOPSIS...JP/MET
NEAR TERM...JP/MET
SHORT TERM...JP
LONG TERM...MET
AVIATION...BC
MARINE...JP/MET
HYDROLOGY...JP/MET